Baby P died shortly before Ofsted gave Haringey a clean bill of health
A total of 210 children in England have died following abuse over a 16-month period, Ofsted's chief inspector Christine Gilbert has told MPs.
She was speaking after Ofsted was criticised for "favourable" inspections of north London's Haringey Council.
Baby P, who was on the council's child protection register, died last year.
Meanwhile, the prime minister said the government would do all in its power to prevent the "needless loss of young life as a result of child abuse".
The number of deaths, recorded between April 2007 and this August, is higher than the government's official figure but Ofsted has insisted it is correct.
Barry Sheerman, chairman of the Commons children and families select committee, said the "horrific figures" had left him worried other councils may be failing to protect abused children.
After Ms Gilbert had answered the committee's questions, Mr Sheerman said: "The session made me less confident, rather than more confident, that there isn't going to be another Haringey waiting."
He added that the chief inspector's answers had also made him less confident about Ofsted's ability to assess social care.
NSPCC statistics show between one and two children die on average every week following abuse in England and Wales. This compares with Ofsted's figures which suggest the number is as high as three a week in England alone.
Ms Gilbert said Ofsted was planning changes to its inspection routine
Ms Gilbert told the committee not all the 210 children who died after neglect or abuse were known to local authorities. Of the 21 babies who died, only two were known to social services, she said.
The prime minister said Lord Laming's review would help to make sure child protection arrangements were effective and the government would act on any recommendations.
He said £73m had been set aside for better training for social workers and Ofsted was being asked to carry out annual inspections across the country.
During the committee questions, it also emerged that from next year social workers worried about poor local authority childcare practices may be able to call a confidential "whistleblower" hotline.
Ms Gilbert said: "We want to make it easier for frontline staff to tell us when things go wrong."
But social worker representatives have expressed reservations about the proposed scheme.
Bridget Robb, of the British Association of Social Workers, told the BBC her members might be unwilling to use an Ofsted hotline to raise concerns about particular cases.
She said: "What will Ofsted do with that information, except go back to the employer and ask - and then the employer will know who complained."
Ofsted, which carries out official inspections of schools and councils, has come under fire after it emerged it awarded Haringey a "good" rating just weeks after the death of 17-month-old Baby P.
The little boy died after months of abuse by his mother, stepfather and a lodger, all of whom were found guilty of causing or allowing his death.
Ms Gilbert has previously said Ofsted was misled by Haringey which "hid behind" false data on how it was handling potential child abuse cases.
She told MPs her inspectorate's assessment of Haringey's child protection services in 2007 was "paper-based" relying on reports and data from other organisations, rather than on-the-ground inspection by Ofsted staff.
After the Baby P case the data was checked, and found to be misleading.
Ms Gilbert said: "Social care cases and the allocation of social workers, when we looked at the files in a number of incidences, appeared to be families rather than separate children in families that had been put forward.
"There was a far harder and higher caseload than had been reported.
"Files also weren't closed promptly as they should have been."
Ms Gilbert said during 2007 there was at least one face-to-face meeting between Ofsted and a "senior person" from Haringey but she did not know what that senior person was.
MPs were concerned Ofsted destroyed data three months after a report was written.
Ms Gilbert said the evidence was in the Ofsted report, the annual performance assessment (APA) letter and the Haringey case files.
The destruction of the records meant Ofsted could not say who inspectors had spoken to at Haringey.
Committee chairman Barry Sheerman said: "That is like an academic writing a paper and destroying all their research material."
Mr Sheerman asked her if "alarm bells" sounded when council documents showed nearly half of Haringey's social workers were agency, not full-time, staff.
Ms Gilbert said that was "fairly usual" in London but agreed the "personal connection" between a social worker and a child was important.
The Ofsted chief also said inspections would not necessarily have discovered some Haringey staff failed to attend all of Baby P's case conferences, where crucial decisions were made about his future welfare.
She said Ofsted was only now aware that: "Although there was commitment to working together, they [Haringey staff] were almost working in parallel."
Ms Gilbert revealed Ofsted was considering lengthening annual inspections to allow more time to talk to staff on the ground and she proposed a questionnaire be sent to social workers to fill in before Ofsted inspectors arrived.
Ms Gilbert was asked whether a "Kafkaesque" system of form-filling prevented social workers from doing their jobs properly.
"I agree that just writing things on piece of paper isn't going to help anyone.
"It is what you do to help the child that matters," she said.